The reaction of CO2 reforming of CH4 has been investigated with y-A1203-supported platinum and ruthenium bimetallic catalysts, with the specific purpose of thermochemical energy storage. The catalysts were prepared by...The reaction of CO2 reforming of CH4 has been investigated with y-A1203-supported platinum and ruthenium bimetallic catalysts, with the specific purpose of thermochemical energy storage. The catalysts were prepared by using the wetness impregnation method. The prepared catalysts were characterized by a series of physico-chemical characterization techniques such as BET surface area, thermo-gravimetric （TG）, transmission electron microscope （TEM） and X-ray photoelectron spectroscopy （XPS）. In addition, the amount of carbon deposits on the surface of the catalysts and the type of the carbonaceous species were discussed by TG. It was found that the bimetallic Pt-Ru/7-A1203 catalysts exhibit both superior catalytic activity and remarkable stability by comparison of monometallic catalysts. During the 500 h stability test, the bimetallic catalyst showed a good performance at 800 ~C in CO2 reforming of CH4, exhibiting an excellent anti-carbon performance with the mass loss of less than 8.5%. The results also indicate that CO2 and CH4 have quite stable conversions of 96.0 % and 94.0 %, respectively. Also, the selectivity of the catalysts is excellent with the products ratio of CO/H2 maintaining at 1.02. Furthermore, it was found in TEM images that the active carbonaceous species were formed during the catalytic reaction, and well-distributed dot-shaped metallic particles with a relatively uniform size of about 3 nm as well as amorphous carbon structures were observed. Combined with BET, TG, TEM tests, it is concluded that the selected bimetallic catalysts can work continuously in a stable state at the high temperature, which has a potential to be utilized for the closed-loop cycle of the solar thermochemical energy storage in future industry applications.展开更多
Highly coke-resisting ZrO2-decorated Ni/A1203 catalysts for CO methanation were prepared by a two-step process. The support was first loaded with NiO by impregnating method and then modified with ZrO2 by deposition-pr...Highly coke-resisting ZrO2-decorated Ni/A1203 catalysts for CO methanation were prepared by a two-step process. The support was first loaded with NiO by impregnating method and then modified with ZrO2 by deposition-precipitation method （IM-DP）. Nitrogen adsorption- desorption, X-ray diffraction, scanning electron microscopy, transmission electron microscopy, thermogravimetdc analysis, H2 temperature- programmed reduction and desorption, NH3 temperature-programmed desorption, and zeta potential analysis were employed to characterize the samples. The results revealed that, compared with the catalysts with the same composition prepared by co-impregnation （CI） and sequential impregnation （SI） methods, the Ni/A1203 catalyst prepared by IM-DP showed much enhanced catalytic performance for syngas methanation under the condition of atmospheric pressure and a high weight hourly space velocity of 120000 mL.g-1 .h-1. In a 80 h life time test under the condition of 300-600 ~C and 3.0 MPa, this catalyst showed high stability and resistance to coking, and the amount of deposited carbon was only 0.4 wt%. On the contrary, the deposited carbon over the catalyst without ZrO2 reached 1.5 wt% after a 60 h life time test. The improved catalytic performance was attributed to the selective deposition of ZrO2 nanoparticles on the surface of NiO rather than A1203, which could he well controlled via changing the electrostatic interaction in the DP procedure. This unique structure could enhance the dissociation of CO2 and generate surface oxygen intermediates, thus preventing carbon deposition on the Ni particles in syngas methanation.展开更多
The oxidation of 2-naphthol and 2-naphthalenethiol to 1,1'-bi-2-naphthol and bis-2-naphthyl disulfide respectively has been carried out in excellent yields in solid state in the presence of Fe3+-montmorillonite or...The oxidation of 2-naphthol and 2-naphthalenethiol to 1,1'-bi-2-naphthol and bis-2-naphthyl disulfide respectively has been carried out in excellent yields in solid state in the presence of Fe3+-montmorillonite or alumina-supported FeCl3.展开更多
The optical microscopy, scanning electron microscopy （SEM） and energy-dispersive spectrometry （EDS） were used to as-sess the influence of micro-addition of （La＋Yb） on the microstructure and mechanical performan...The optical microscopy, scanning electron microscopy （SEM） and energy-dispersive spectrometry （EDS） were used to as-sess the influence of micro-addition of （La＋Yb） on the microstructure and mechanical performance of the AlSi10Cu3 alloy in heat treatment conditions. It was shown that the appropriate （La＋Yb）addition （0.3 wt.% or 0.6 wt.%） transformed the needle-likeβ-Al5FeSi phase into Chinese script or sphericalα-Al8Fe2Si phase. Eutectic silicon refined the long needle-like particles into granular or round particles at 0.6 wt.% （La＋Yb） content. Moreover, the La3Al11 and YbAl3 phases acted as strengthening phases during the heat treatment processing in the alloy with the addition of （La＋Yb）. Consequently, the alloy with 0.6 wt.% （La＋Yb） exhibited an en-hanced mechanical properties response with ultimate tensile strength, elongation, and hardness at 69.35%, 113.26% and 23.61% higher than those of the unmodified alloy, respectively. Further addition （0.9 wt.%） of （La＋Yb） resulted in the increasing of the black acicular RE-rich intermetallics during heat treatment, which could aggravate the situation of stress concentration leading to deteriora-tion of the mechanical properties of alloy.展开更多
基金Project(2010CB227103) supported by the National Basic Research Program of ChinaProjects(50930007,50836005) supported by the Key Program of the National Natural Science Foundation of ChinaProject(U1034005) supported by the National Natural Science Foundation of China
文摘The reaction of CO2 reforming of CH4 has been investigated with y-A1203-supported platinum and ruthenium bimetallic catalysts, with the specific purpose of thermochemical energy storage. The catalysts were prepared by using the wetness impregnation method. The prepared catalysts were characterized by a series of physico-chemical characterization techniques such as BET surface area, thermo-gravimetric （TG）, transmission electron microscope （TEM） and X-ray photoelectron spectroscopy （XPS）. In addition, the amount of carbon deposits on the surface of the catalysts and the type of the carbonaceous species were discussed by TG. It was found that the bimetallic Pt-Ru/7-A1203 catalysts exhibit both superior catalytic activity and remarkable stability by comparison of monometallic catalysts. During the 500 h stability test, the bimetallic catalyst showed a good performance at 800 ~C in CO2 reforming of CH4, exhibiting an excellent anti-carbon performance with the mass loss of less than 8.5%. The results also indicate that CO2 and CH4 have quite stable conversions of 96.0 % and 94.0 %, respectively. Also, the selectivity of the catalysts is excellent with the products ratio of CO/H2 maintaining at 1.02. Furthermore, it was found in TEM images that the active carbonaceous species were formed during the catalytic reaction, and well-distributed dot-shaped metallic particles with a relatively uniform size of about 3 nm as well as amorphous carbon structures were observed. Combined with BET, TG, TEM tests, it is concluded that the selected bimetallic catalysts can work continuously in a stable state at the high temperature, which has a potential to be utilized for the closed-loop cycle of the solar thermochemical energy storage in future industry applications.
基金supported by the National Natural Science Foundation of China(No.21476238)the National Basic Research Program(No.2014CB744306)+1 种基金the National Key Technology R&D Program of China(No.2010BAC66B01)the"Strategic Priority Research Program"of Chinese Academy of Sciences(Nos.XDA07010100 and XDA07010200)
文摘Highly coke-resisting ZrO2-decorated Ni/A1203 catalysts for CO methanation were prepared by a two-step process. The support was first loaded with NiO by impregnating method and then modified with ZrO2 by deposition-precipitation method （IM-DP）. Nitrogen adsorption- desorption, X-ray diffraction, scanning electron microscopy, transmission electron microscopy, thermogravimetdc analysis, H2 temperature- programmed reduction and desorption, NH3 temperature-programmed desorption, and zeta potential analysis were employed to characterize the samples. The results revealed that, compared with the catalysts with the same composition prepared by co-impregnation （CI） and sequential impregnation （SI） methods, the Ni/A1203 catalyst prepared by IM-DP showed much enhanced catalytic performance for syngas methanation under the condition of atmospheric pressure and a high weight hourly space velocity of 120000 mL.g-1 .h-1. In a 80 h life time test under the condition of 300-600 ~C and 3.0 MPa, this catalyst showed high stability and resistance to coking, and the amount of deposited carbon was only 0.4 wt%. On the contrary, the deposited carbon over the catalyst without ZrO2 reached 1.5 wt% after a 60 h life time test. The improved catalytic performance was attributed to the selective deposition of ZrO2 nanoparticles on the surface of NiO rather than A1203, which could he well controlled via changing the electrostatic interaction in the DP procedure. This unique structure could enhance the dissociation of CO2 and generate surface oxygen intermediates, thus preventing carbon deposition on the Ni particles in syngas methanation.
文摘The oxidation of 2-naphthol and 2-naphthalenethiol to 1,1'-bi-2-naphthol and bis-2-naphthyl disulfide respectively has been carried out in excellent yields in solid state in the presence of Fe3+-montmorillonite or alumina-supported FeCl3.
基金Project supported by the National Natural Science Foundation of China(51364035)Ministry of Education tied up with the Special Research Fund for the Doctoral Program for Higher School(20133601110001)Loading Program of Science and Technology of College of Jiangxi Province(KJLD14003)
文摘The optical microscopy, scanning electron microscopy （SEM） and energy-dispersive spectrometry （EDS） were used to as-sess the influence of micro-addition of （La＋Yb） on the microstructure and mechanical performance of the AlSi10Cu3 alloy in heat treatment conditions. It was shown that the appropriate （La＋Yb）addition （0.3 wt.% or 0.6 wt.%） transformed the needle-likeβ-Al5FeSi phase into Chinese script or sphericalα-Al8Fe2Si phase. Eutectic silicon refined the long needle-like particles into granular or round particles at 0.6 wt.% （La＋Yb） content. Moreover, the La3Al11 and YbAl3 phases acted as strengthening phases during the heat treatment processing in the alloy with the addition of （La＋Yb）. Consequently, the alloy with 0.6 wt.% （La＋Yb） exhibited an en-hanced mechanical properties response with ultimate tensile strength, elongation, and hardness at 69.35%, 113.26% and 23.61% higher than those of the unmodified alloy, respectively. Further addition （0.9 wt.%） of （La＋Yb） resulted in the increasing of the black acicular RE-rich intermetallics during heat treatment, which could aggravate the situation of stress concentration leading to deteriora-tion of the mechanical properties of alloy.
